Chimney cap



Dec. 12, 1939. E. w. KEPPLE 2,l83,402

CHIMNEY CAP Filed Fb. 18, 1939 2 Sheets-Sheet 2 A TTZZRNEK Patented Dec.12, 1939 ,ATTENT OFFICE CHIMNEY C'AP y Ezra, W. Kepple,

xApplicatio February 1 8,

` 12 Olaims.

My invention is an improvement inventilating chimney caps for terminalapplication to the outlet Conduit of gases of combust-ion, as a fiueorstack, to improve the draft thereof.

More particularly it' is designed for use as a chimney cap for'housefluesmade of brick or other refractory material, and is especiallydesigned to assist .and control thedrat under all weather conditions.Generally stated the device consists of a hollow coping or' cap ofconcrete, terra cotta, sheet metal, or other suitable ma-` terialhavinga supporting base and of particular externaland internal shape best'adapted to effect the desired results, as shall be more fullyhereinafter. described.

Referring to thedrawings showing ferred constructions:

`Fig. 1 isa 'perspective view of the cap, de-

tached; i i I Fg.. 2..is'.acentral Vertical section of a concrete cap,on the' line .II-II of Fig. 1, andlof the uppersend of' a. chimney fiue;

i Big. 3 is' a cross section on theline III--IIL looking upwardly;

Fig. &His a` View like Fig..2, showing the cap as. made ofisheet metal;

Fig.` 5 isa view like Fig.- 1., showing a modified construction;

.Fig. 6. is a cross section like Fig. 3 .onthe line the preof Fig. 5.

i at the bottom with the inner faces of the chimney walls. Such faces 5extend upwardly to near the` .top-4 by. four straight or slightly'inwardly 7 sloping planes, for convergence 'and .gradual cross areareduction.

Near; the, topxthe interior, cross area; isabrupt'- ly, .restricted. by;the inwardly beveled: shoulders 5 extending from the angular joint orbend l with faces; 5::to the lower edges of the finally restrictedsquare' outlet ,opening 8, terminating at? the; extreme top of the cap.

v Suchwopening is: denedwithin the compare# tively-' short `inwardlyinclined faces 9' beyond whichgthe four outer sides ofthe,top of theGreensbrg, Pa. 1939, Serial No. %7,123 (o. 72-88 The- Walls increase' inthickness downwardly towards the -base- 4 and with an outer scotiacurve-of constant downwardly reduced radius as clearly indicated at !3,forming streamline surfaces on all four sides.

By such construction it will.be seen that -the base is of ample strengthand Weight, assisting in stability when in position, and with a pleasingarchitectural appearance. Incidentally,

` the-bottom of the base may be provided with a' s surrounding- V orother shape groove M for' 'firm' anchoring engagement with 'the mortaror cementz.

Assuming' the usually diflicult conditions of lateral winds, eitherdirectly against either of the` four` main extcrior surfaces, orangularly against any two of them, the lower concaved and upwardlytapering outer faces eifect ;desired deflecton of'the. Currents,asindicated by' the arrows'Fig. 2.

As suchcurrents move inwardly they are' also guided upwardly, while the'final bevels !0, of say 30 tol ifi` toxthe horizontal, more or less,produce: an abrupt upward. and inward course. !The combinedieffect 'ofthe wind Currents isto thereby produce an' uplifting :suction draft onthe gases passing out through the cap.

'Suchgases likewise are caused to converge during 'their passage throughthe cap .from bottom .to top, and. are' finally further restrictedab-ruptly by. the inwardly beveled shoulders 5 andconverging outlett,with resulting acceleration. r r

Ordinarily; in, calm weather, the: interier formation of. the cap'greatly contributes to and improves the natural draft; of' the chimney.The 'eifectof a breeze .or wind. inwthe manner described. is; toiexerta: slightassisting suction or partial Vacuum, with a resultingimprovement in. accelerating: and ;stabilizing `the draft of. the mainchimney emine., such advantageous'results have in-fact been. ,Securedbyprolonged actual use of-my construction under the variousconditions'mentioned.

Whilesatisfiactory results; are Secured: bythe concreteaconstruction, asabove described.. the

cap may also be Very efficiently made of sheet metal, as in Fig. 4.

The general proportions may be maintained as to both external andinternal faces, but utilizing a downward extension of the inner facewall members for insertion into the top of the chimney, and with a veryslight variation from upward tapering to substantally vertical formationof these members.

In such Construction I utilize a rectangular base plate da for placementon the chimney top, to which the inner box-like shell Ea and the outershell l3a are connected, as by Welding or other suitable means.

Inner shell extends through and suiciently below base plate ta for closeintertting engagement within the top portion of chimney 4, so thateither with or without the mortar 3 the entire cap will be firmlymounted in position. At its upper end shell 5a is bent inwardly to formthe beveled draft constricting shoulders Ba beyond the angular bends ?aand terminates in the finally restricted square outlet opening Ba,within the surrounding upper edge terminals Qa of the inner shell.

The upper terminal portions of outer shell l3a are bent inwardly overthe terminals of the inner shell at confining angles and are securedthereto, as by welding, providing the final bevel faces Ina te'minatinginwardly in the angle `lips Ha.

Outer sections |3a extend downwardly from the lower edge Iza of bevel!Ua substantally straight for a limited distance and then graduallyconcavely outwardly, terminating in the outer edges of the base portion,as in Figs. 1 and 2.

Such lower edges of the outer walls are securely connected with the baseplate da, as by welding.

It Will be understood of course that in sheet metal Construction theinner and outer sections together provide and constitute in effect themain surrounding wall portions of the complete cap, although withintervening hollow spaces, instead of being continuously solid.

otherwise than by the substitution of sheet metal for concrete, thegeneral Construction closely conforms in all essential respects as toproportions, inner and outer surfaces, etc. and functions and givesresults in operation as` described, and with equal facility inmanufacture and use.

I show in Figs. 5 and 6 a further modification of the molded or concreteembodiment of the in- Vention, generally similar to that of Figs. 1, 2and 3, but with additional useful features facilitating confining anddeflecting control of wind Currents.

In such the main elements and features are retained comprising thelaterally extending base lb for placement on the chimney 2b, with theinner faces Ec leading up to the inwardly beveled shoulders Gb forConstruction of the gases of combustion in their passage towards and outof the top opening 8b within the surrounding edge faces gb. The outerwall faces are concavely formed as at I 3b leading upwardly to the edgesl2b at the bases of bevel faces !Ub leading inwardly to the edges llb ofthe middle outlet opening.

For the purpose of providing supplemental wind control and restrictioneach of the several corner edges of concaved surfaces l3b are providedwith comparatively narrow outwardly extending webs or fin-like fiangesl5b extending from top to bottom of the cap. These act as obstructingwind dams tending to more or less centralzing connement of the Currents,with resulting increase in their effect in passing upwardly over one, orboth concave faces of adjacent walls, as already described.

They are further useful in stiffening and bracing the cap at eachcorner, and add to the architectural appearance of the device.

While the general proportions of either form of the device should beapproximately as illustrated, it will be understood that they, ormatters of size, dimensions, material, or other incidental matters maybe changed 'or vaied from ,without departure from the principle of theinvention and within the scope of the appended claims'.

What I claim is:

1. A rectangular chimney cap as described having a supporting base ofmaximum size for placement on a chimney'and extended upwardly forming awall around a middle gas circulation opening with inner confining facesterminating in a constricted shouldered outlet opening, the outer facesof the cap converging inwardly from the rim of the base and concavedupwardly with increasing radii to a common transversely plane, and thenangularly defiected inwardly and upwardly to the edges of the outletopening to form beveled air deflecting faces adjacent the outletopening.

2. A rectangular chimney cap having four transversely straight wallsenclosing a middle gas outlet opening defined within upwardly andinwardly disposed inner wall faces terminating in a restricted upwardlytapering discharge opening, the outer wall faces flaring concavelyoutwardly in formation of a laterally extending base and thereabove insubstantally plane upper inwardly tapering formation and having terminalinwardly and upwardly sloping bevel faces extending inwardly to theedges of the discharge opening.

3. A rectangular molded chimney cap having four integral transverselystraight walls enclosing a middle gas outlet opening defined withinupwardly and inwardly disposed inner wall faces terminating in arestricted upwardly tapering discharge opening, the outer wall facesfiarng concavely outwardly in formation of a laterally extending baseand thereabove in substantally plane upper inwardly tapering formationand having terminal inwardly and upwardly sloping bevel faces extendinginwardly to the edges of the discharge opening.

4:. A rectangular molded chimney cap having four integral transverselystraight walls enclosing a middle gas outlet opening defined withinupwardly and inwardly disposed inner wall faces terminating in arestricted upwardly tapering discharge opening, the outer wall facesfiaring concavely outwardly in formation of a laterally extending basehaving a mortar engaging recess, the upper portions of the wall facesbeing in substantially plane slight inwardly tapering formation andhaving terminal wind deecting bevel faces extending inwardly to theedges of the discharge opening whereby to effect an uplifting suctiondraft on converging gases issuing through the tapering discharge openingat the top of the cap.

5. An integral chimney cap of concrete consisting of surrounding wallshaving a relatvely wide supporting base, the inner faces of said wallsextending upwardly towards the top, then disposed more abruptly inwardlyand then upwardly with slight inward taper forming a restricteddischarge opening, the outer wall faces bein concaved from the outeredges of the base and I thereabove with increasing radii and terminatingin upper inwardly disposed plane surfaces, and having final winddeflecting bevel faces extending inwardly to the edges of 'the dischargeopening.

6. A chimney cap of sheet metal consisting of an inner gas circulationsection terminating in an upper constricted shouldered outiet opening, asurrounding base plate of maximum size for placement on a chimney, andan outer wind defiecting section connected With the base piate havinglower faces converging inwardiy and concaved upwardly and bent inwardlyover and secured to the top portion of the inner section to form beveledair defiecting faces adjacent the outlet opening'.

'7. A chimney cap of sheet metal consisting of g an inner gascirculation section terminating in an upper constricted shoulderedoutlet opening, a

surrounding base plate of maximum' size for placementon a chimney, andan outer Wind defiecting section connected With the base plate havinglower faces converging inwardly and concaved upwardly and bentinwardlyover and se-- cured to the top portion of the inner section terminating at the edges of the outlet opening and forming beveled airdefiecting faces adjacent the outlet opening. v

8. A chimney cap as in claim 6 wherein the in ner section extendsdownwardly below the base plate for engagement within a chimney top.

9. A chimney cap as in claim 3 wherein the several corners betweenadjacent concaved outer faces are provided With outvvardly extendng windarresting extensions.

10. A chimney cap as in claim 3 Wherein the severaicorners betweenadjacent concaved outer faces are provided with outvvardly extendingintegrai wind arresting extensions in the form of comparativeiy thinfianges.

li. A 'ectangular chimney cap as described having a supporting base ofmaximum size for placement on a chimney and extended upwardly forming aWall around a middle gas circulation opening With inner confining facesterminating below inwardly disposed upwardly sloping restricting'shouiders having inwardlly disposed faces terminating in a constrictedoutlet opening, the outer faces of the cap cenverging inwardly andupwardly from the rim of the base to a commen transverse plane, and thenangularly deflected inwardly and upwardly to the edges of the outletopening to form beveled air deflecting faces adjacent the outletopening.

12. A rectangular chimney cap as described having a supporting base ofmaximum size for piacement on a chimney and extended upwardly forming awall around a middle gas circuiation opening with inner conning facesterminating below inwardly disposed upwardly sloping restrictingshoulders having inwardly disposed faces terminating in a constrictedoutlet openi ing, the outer faces of the cap converging invvardly andupwardly above the base in substantially plane inwardly taperingformation and having terminal inwardly and upwardly sloping bevel facesextending inwardly to the edges of the outlet opening.

E-ZRA W. KEPPLE.

